1. Field of the Invention
The present invention relates to a charging apparatus that charges a battery device (battery pack).
2. Description of the Related Art
There is a battery device used for a camera apparatus which includes two or more battery cells. A battery pack formed by serially connecting two or more lithium ion batteries may be one of the battery device including two or more battery cells. A charging apparatus that charges such a battery device includes an overcharge preventing function to prevent the overcharge thereof. A function of stopping the charging of the battery device when a charging voltage to the battery device exceeds a predetermined voltage or more is one of the overcharge preventing functions. Japanese Patent Application Laid-Open No. 2009-177930 discusses an overcharge preventing function for solving an issue of determining by a charging apparatus that a battery device is not connected to the charging apparatus though the battery device is connected to the charging apparatus and supplying a constant voltage from the charging apparatus to the battery device.
The charging apparatus that charges the battery device including two or more battery cells needs various overcharge preventing functions. For example, when the battery device can communicate with the charging apparatus, an overcharge preventing function is advantageous for controlling the charging of the battery device according to as whether loose connection occurs between a communication terminal of the battery device and that of the charging apparatus. Also when the battery device can communicate with the charging apparatus, an overcharge preventing function is advantageous for controlling the charging of the battery device according to as whether a communication line is short-circuited between the battery device and the charging apparatus.